I said I swore off Iraq posts, but I will respond to the historical point.

Fact is we did NOT "run" Japan and Germany in the sense of conducting day to day administration and infrastructure. Other than police and security things were mostly left in the hands of the Germans and Japanese who'd been doing them before we arrived. De-Nazification never went as deep as Bremer's De-Baathification order did. Certainly by 1946 we'd handed most things back to the Germans other than high politics (Patton famously got in trouble for saying something to the effect that he didn't care what a man's politics had been so long as he could do his job right). In Japan other than the handful of prominent top war criminals we hardly kicked out bureaucrats and technicians at all.

What made Japan and Germany work so well was that they were societies where, even after the war, you could expect most railroad employees to try to keep the trains running, as opposed to selling off the equipment and mugging the passengers.

True, Americans were making the big policy decisions about the economy and education and such, but no matter how pure the policies were that wouldn't have mattered if the Germans and Japanese didn't generally implement them. At the peak we had fewer than 400,000 troops in Japan, dropping rapidly in 1946, and that was back when you needed a lot more manpower to administer bureaucracies and industries. If all the clerks and fare collectors and plant managers had been American, we would have need several million Americans.

You can even chalk this up as another score against Leftism: post-fascist societies have fared better than post-communist societies. Though I'd say it has more to do with deeper factors: in central Europe the fall of communism was met with genteel corruption rather than violent plundering as in Russia or near-warlordism in Central Asia and the Caucausus.

That Iraq would be a society that would fare poorly on that scale and would have the corruption problems we see was pretty clear to anyone familiar with the social science literature, but again, I'm swearing that off.